Rigid crating system for sheet material and the like



Sept. 14, 1965 J. w. M CRACKEN 3,206,050

RIGID CRATING SYSTEM FOR SHEET MATERIAL AND THE LIKE Filed Feb. 1'7. 1964 Fig. 2.

INVENTOR James W. McCrucken United States Patent 3,206,050 RIGID CRATING SYSTEM FOR SHEET MATERIAL AND THE LIKE James W. McCraclren, 81 Canal St., Leechburg, Pa. Filed Feb. 17, 1964, Ser. No. 345,516 2 Claims. (Cl. 214-152) This invention relates to apparatus and method for rigidly crating bendable sheet material for shipping, handling and/or storage utilizing the rigidity of such sheet material in bowed form. More particularly, this invention pertains to elongated crating blocks of wood to bow and hold such sheet material and the like, such as large or long sheets of relatively thin gauge metal, wallboard, plastic and other products, in rigidly crated form which can be readily handled without deflection and/ or deformation.

As an example of the field of use and utility of this invention, it may be mentioned that sizeable sheets of wallboard, plastic and metal present problems in connection with the shipment, handling and/ or storage thereof, which usually is performed with such sheet material in piles or stacks, because of the drooping of the ends, or other bending or twisting of the sheet material when being handled. Consequently, it has been one practice at considerable expense to pile many sheets of such material on a relatively heavy, rigid pallet for strapping of the material to such pallet; another, to encase a single pile of sheets, such as thin-gauge, stainless-steel sheets of high and valuable surface finish, in a rigid wooden or metail case, e.g., see United States Patents Nos. 2,661,- 838 and 2,901,102.

In the instant invention, such flexible sheet material, whether a single sheet or a pile of sheets, may be rigidly era-ted for shipping, storage and/or other handling by bowing the material out of its flat, normal plane and holding it bowed by means of rectilinear blocks, preferably extending transversely of such sheet material and the like, inasmuch as the problem solved hereby usually arises particularly in connection with such sheet material having a much greater length than width. Each such rectilinear block preferably comprises two crosspieces, the bottom surface of the upper crosspiece being convex downwardly and the top surface of the lower crosspiece being concave upwardly so that the two crosspieces when in vertical registry, whether with or without sheet material inbetween, virtually interfit. When sheet material is between such crosspieces, and they are steel strapped around the ends thereof, the sheet material is held with the same bowing curvature as that of the crosspieces in each block, such bowing being sufliciently shallow to avoid any deformation or permanent set in such sheet material. A plurality of such blocks in parallel arrangement spaced from each other will hold such sheet material rigidly so that it may be stacked, loaded, unloaded, stored, shipped and otherwise moved without drooping, bending, or twisting At least two such blocks will be used in smaller crates; more in larger, or longer, ones. Moreover, the material may be readily piled up in stacks of crates when rigidly crated in accordance with this invention and handled by conventional material handling equipment including fork-lift trucks in bundles of one or more crates without difiiculty or interference. Still further, the cost of crating in a system of this invention is very much lower than prior practices and requires no skilled personnel. Crating blocks of this invention may be prepared by routine mill work from standard lumber, or such blocks may be made of lumber with a polystyrene core, or of metal.

Other objects, features and advantages of this invention will be apparent from the following description and 3,206,050 Patented Sept. 14, 1965 the accampanying drawings, which are illustrative of one embodiment only, in which FIGURE 1 is :a view in side elevation of a stack of four bundles of sheet material, each bundle comprising one or a pile of flexible sheets of the material, as desired, relatively rigidly held by one embodiment of the crating system of this invention;

FIGURE 2 is a plan view of the stacks shown in -FIG URE 1 looking down on the uppermost bundle in that stack;

FIGURE 3 is an isometric view of one crating block used in the above crating embodiment with the upper and lower crosspieces comprising that block in vertically separated position;

FIGURE 4 is a detail side elevational View, somewhat enlarged, showing a portion of the stack in FIG- URE l to show superposed crating blocks in one of the groups thereof in that embodiment; and

FIGURE 5 is an end view of the bundles in stacked arrangement shown in FIGURE 1.

Referring to the drawings, a stack 10 is shown comprising four crates, or bundles, 11 of flexible sheet material 12. For the purpose of this description, such sheet material may be assumed to be one or a pile of superposed sheets relatively long when compared to the width thereof and capable of being bowed, in this case such bow being transverse and concave upwardly in the relatively natural form the sheet or pile of sheets would assume if they were supported from beneath along their side edges only. Such sheets in each pile in each crate 11 may be separated by paper or other covering to protect the surface finish thereof, if desired, and, further, the whole pile may be wrapped in such a protective covering before the crating thereof by means of being clamped between a pair of upper and lower crosspieces in each of the crating blocks 13 used therewith.

Each crating block 13 comprises an upper member 14 and a lower member 15, such members in the illustrated embodiment being crosspieces because they extend across the sheet material 12 and hold it in bowed condition when the crate 11 is assembled. The top, bottom, sides and ends of each block 13 preferably are planar as shown although they may have other forms, the whole block preferably being rectilinear as to the outer surfaces thereof. However, the bottom surface 16 of upper crosspiece 14- is a curved cylinder section so as to be convex downwardly while the top surface 17 of lower crosspiece 15 is a curved cylindrical section so as to be concave upwardly. Preferably, each crosspiece, when of wood, is made in one piece, but it may be made of more than one.

The curvature of surfaces 16 and 17 is complementary so that they fit one another and define the bow to be taken by the sheet material 12 when the blocks 13 are tightly applied thereto by encircling steel straps 18. Such curvature, which is also the curvature of the transverse bow of material 12 in each crate 11, is relatively shallow, sufiicient to hold the sheet material 12 rigid without drooping or being subject to bending or twisting in any direction, yet insufiicient to permanently deform the sheet material out of its normal flatness in which it conventionally is when put to use, and, insufficient to form any permanent deformation or set in the sheet material irrespective of how long such sheet material may stand bowed in crate 11.

Preferably, each lower crosspiece 15 is provided with an upwardly recessed channel 19 extending out through the ends of crosspiece 15, the width of that channel being such as to accommodate the width of the steel band from which the straps 18 are formed and having a height at least equal to the thickness of two of such bands inelusive of any band clip therefor that may be in the channel. Such channels 19 provide crate stacking advantages illustrated in more detail in FIGURE 4. Each encircling steel strap 18 passing around the ends of each block 13 will be held in tightened condition under a predetermined tensile strain by any usual form of clip 20 utilized therefor as illustrated in chain outline in FIG- URE 3. The selected tightness of such steel strapping bands 18 preferably is such that each crate 11 will remain rigid without any of the sheets in a pile being subject to sliding with respect to one another, or with respect to any of the blocks 13, and, without the parallel spaced blocks 13 in the illustrated embodiment being subject to movement relative to sheet material 12, or one another. The length of the crosspieces 14 and 15 is such, preferably, as to protect the side edges of said material 12 against being damaged by the straps 18 where they pass around the ends of the blocks 13, or otherwise. Moreover, when crates 11 are stacked upon one another as illustrated in FIGURES 1, 4 and 5, a higher stack of such bundles 11 may be made because there is no drooping anywhere when being handled by materials handling equipment such as a fork lift truck. Preferably in such stacking, corresponding blocks 13 in each crate are superposed as shown in FIGURE 4 and the reach of strap 18 along the top of an immediately lower block 13 fits in channel 19 of the immediately superjacent block 13, improving support and the stability of the stack against being toppled or shifted.

In handling eac-h crate 11, when being stacked, or when stacked as shown, there is suflicient entry space 21 between the bottom of the sheet material in an upper crate 11 and the top of the sheet material 12 in an immediately lower crate 11, or the ground, for the forks of a fork lift truck, for example, to pass thereinto a sufficient distance to lift off the upper crate, or to deposit it in a reverse operation, no special equipment being required.

In the assembling and movement of crates 11 of this invention, it is preferred that the bow in the sheet material 12 be concave upwardly and that such how be transverse of the length of the material where that length is greater than the width thereof. When a crate 11 of this invention is opened by the cutting of the straps 18 so that the sheet material 12 can be removed therefrom and used, the blocks 13 may be nested together as will be clearly apparent from FIGURE 3 and groups of them placed together and strapped to form a cubical pallet for shipment back to the crating source, usually the place where the sheet material is manufactured.

It is thus evident that by a system of this invention, rigid crating of flexible sheet material and the like may be provided utilizing such sheet material itself in the formation of a rigid crate at relatively low cost and with materially increased convenience and other advantages. Other embodiments of this invention may be provided and changes made in details of the illustrated embodi- 4 ment without departure from the spirit of this invention, or the scope of the appended claims.

What is claimed is:

1. In a method of rigidly crating a pile of elongated flexible sheet material and the like, the steps comprising, in combination, piling said sheet material in vertical registry, bowing said sheet material about the longer median axis thereof to be concave upwardly to each side of said axis, cradling substantially the entire width of the bottom of said bowed pile in axially spaced lower members extending transversely to said axis in supporting relation to the bottom of said pile, said lower members having a top surface with an upwardly concave single curvature which supports the bowed bottom of said pile, pressing substantially the entire width of the top of said bowed pile with axially spaced upper members extending transversely to said axis, said upper members having a bottom surface with a downwardly convex single curvature which supports the bowed top of said pile conforms, said curvatures substantially corresponding and being incapable of permanently setting said bow in said sheet material, positioning lower and upper members respectively in vertically registered axially spaced sets, and strapping said sets of members around their ends transverse to said axis thereby to rigidly hold together said pile of sheet material and the like.

2. In a method of rigidly crating flexible sheet material and the like, the steps comprising, in combination, bowing said sheet material about a median axis thereof, cradling the bottom of said bowed pile in axially spaced lower members extending transversely to said axis in supporting relation to the bottom of said pile, said lower members having a top surface with a bowing curvature to which said bottom of said pile conforms, pressing the top of said pile with axially spaced upper members extending transversely to said axis, said upper members having a bottom surface with a bowing curvature to which the top of said pile conforms, said curvatures substantially corresponding and being incapable of permanently fixing said bow in said sheet material, positioning lower and upper members respectively in vertically registered axially spaced sets, and clamping said members together in each set thereby to rigidly hold together said pile of sheet material and the like.

References Cited by the Examiner UNITED STATES PATENTS 673,273 4/01 Langlotz et a1 2l4-10.5 1,784,909 12/30 Romine 206- 2,287,056 6/42 Owens 206-60 2,499,959 3/50 Kruse et al.

2,743,010 4/56 Koester 206-62 FOREIGN PATENTS 148,639 7/20 Great Britain.

THERON E. CONDON, Primary Examiner,, 

1. IN A METHOD OF RIGIDLY CRATING A PILE OF ELONGATED FLEXIBLE SHEET MATERIAL AND THE LIKE, THE STEPS COMPRISING IN COMBINATION, PILING SAID SHEET MATERIAL IN VERTICAL REGISTRY, BOWING SAID SHEET MATERIAL ABOUT THE LONGER MEDIAN AXIS THEREOF TO BE CONCAVE UPWARDLY TO EACH SIDE OF SAID AXIS, CRADLING SUBSTANTIALLY THE ENTIRE WIDTH OF THE BOTTOM OF SAID BOWED PILE IN AXIALLY SPACED LOWER MEMBERS EXTENDING TRANSVERSELY TO SAID AXIS IN SUPPORTING RELATION TO THE BOTTOM OF SAID PILE, SAID LOWER MEMBERS HAVING A TOP SURFACE WITH AN UPWARDLY CONCAVE SINGLE CURVATURE WHICH SUPPORTS THE BOWED BOTTOM OF SAID PILE, PRESSING SUBSTANTIALLY THE ENTIRE WIDTH OF THE TOP OF SAID 